ATF-1 transcription factor regulates the expression of ccg-1 and cat-1 genes in response to fludioxonil under OS-2 MAP kinase in Neurospora crassa.
The ATF/CREB family transcriptional factors are regulated by stress-activated MAP kinase in yeast. The disruptants of the atf-1 gene, which encodes an ATF/CREB family transcriptional factor, were isolated and characterized in Neurospora crassa. The characteristic phenotypes in the os-2 MAP kinase strain, such as osmotic sensitivity and fludioxonil resistance, were not observed in the Deltaatf-1 strain; however, like the os-2 strain, up-regulation of the catalase gene cat-1 and the clock-controlled gene ccg-1 by treatment with fludioxonil (1 microg/mL) or 4% NaCl was almost completely abolished in the Deltaatf-1 strain. A gel shift assay indicated that ATF-1 bound to the cat-1 and ccg-1 promoters probably through the CRE motifs. The enzyme activity of large-subunit catalase CAT-1, the major conidial catalase, was not detected in the Deltaatf-1 strain, suggesting that the production of CAT-1 during formation of conidia is largely dependent on ATF-1. Among 11 clock-controlled genes, the expression of ccg-1, ccg-9, ccg-13, and ccg-14 was induced by fludioxonil in an OS-2-dependent manner; however, induction of ccg-13 and ccg-14 was observed in the Deltaatf-1 strain, suggesting the existence of another transcription factor regulated by OS-2. The homozygous cross between the Deltaatf-1 strains produced perithecia and ascospores; however, their ascospores never germinated. These findings suggest that ATF-1 acts as one of the transcriptional factors downstream of the OS-2 MAP kinase and probably regulates some genes involved in conidiation, circadian rhythm, and ascospore maturation in N. crassa.
Yamashita
Kazuhiro
K
Faculty of Life Sciences, Toyo University, Itakura, Oura-gun, Gunma 374-0193, Japan.
Shiozawa
Azusa
A
Watanabe
Setsuko
S
Fukumori
Fumiyasu
F
Kimura
Makoto
M
Fujimura
Makoto
M
D000935:Antifungal Agents / Q000494:pharmacology*; D004271:DNA, Fungal / Q000378:metabolism; D004149:Dioxoles / Q000494:pharmacology*; D024202:Electrophoretic Mobility Shift Assay; D005656:Fungal Proteins / Q000096:biosynthesis*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D016254:Mutagenesis, Insertional; D009492:Neurospora crassa / Q000235:genetics / Q000502:physiology*; D010770:Phosphotransferases; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011758:Pyrroles / Q000494:pharmacology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D000935:Antifungal Agents; D004271:DNA, Fungal; D004149:Dioxoles; D005656:Fungal Proteins; D011758:Pyrroles; D014157:Transcription Factors; D010770:Phosphotransferases; C108339:fludioxonil